It is frequently necessary to control the operations of two different devices. Completely parallel drive systems controlled by a common control could be employed to coordinate the operation of the respective devices. However, where minimal weight is preferred as in aircraft applications, the use of separate power drive units undesirably adds considerable weight to the entire apparatus. Thus, there is a need for a single power drive unit with two output shafts for driving respective devices in a controlled manner. A further requirement is to prevent the operation of either device in the event of loss of motive power, for example with loss of hydraulic pressure in an aircraft, while permitting manual drive through the power drive unit, if desired, in the absence of hydraulic pressure as where the aircraft is on the ground.